Tag the Pyodide wheel per PEP 783 so PyPI accepts it

The original commit produced a wheel tagged `emscripten_3_1_58_wasm32`.
PyPI's warehouse validator (live since 2026-04-21) only accepts
`pyemscripten_<year>_<patch>_wasm32` per PEP 783, so that wheel would
have been rejected at upload time. Local `emfs://` verification did
not catch this because it bypasses index-side tag validation.

Updates:

- Bump Pyodide to 0.29.4, which natively installs `pyemscripten_*`
  wheels (pyodide/pyodide#6180, #6203) and ships Python 3.13 as its
  bundled interpreter.
- Bump host Python on the runner to 3.13 to satisfy pyodide-build's
  xbuildenv compatibility check.
- Pin maturin to >= 1.13.2, which introduced the PEP 783 tag cascade
  (PyO3/maturin#3163), and export
  `MATURIN_PYEMSCRIPTEN_PLATFORM_VERSION` derived from `pyodide
  config get` so the cascade emits the `pyemscripten_*` tag even on
  Pyodide 0.29 (where it would otherwise fall back to `pyodide_*`).
- Verify step now asserts the wheel filename matches
  `pyemscripten_<year>_<patch>_wasm32.whl` before loading, so a
  PyPI-incompatible tag fails CI loudly instead of slipping through.

Author: sinaatalay

.github/workflows/CI.yml

@@ -131,15 +131,15 @@ jobs:
   pyodide:
     runs-on: ubuntu-latest
     env:
-      PYODIDE_VERSION: "0.27.7"
+      PYODIDE_VERSION: "0.29.4"
       RUSTUP_TOOLCHAIN: nightly-2025-08-08
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          # Pyodide 0.27.x bundles Python 3.12, and pyodide-build's
+          # Pyodide 0.29.x bundles Python 3.13, and pyodide-build's
           # xbuildenv install rejects mismatched host Python versions.
-          python-version: "3.12"
+          python-version: "3.13"
       - uses: actions/setup-node@v4
         with:
           node-version: "22"
@@ -168,7 +168,13 @@ jobs:
           export PYO3_BUILD_EXTENSION_MODULE=1
           export PYO3_PYTHON="$(pyodide config get interpreter)"
           export PYTHON_SYS_EXECUTABLE="$PYO3_PYTHON"
-          uvx maturin build --release \
+          # Force maturin to emit the PEP 783 `pyemscripten_<year>_<patch>_wasm32`
+          # tag. PyPI's warehouse validator only accepts this format; the legacy
+          # `pyodide_*` / `emscripten_*` tags get rejected at upload.
+          plat_ver="$(pyodide config get pyemscripten_platform_version 2>/dev/null || true)"
+          [[ -n "$plat_ver" ]] || plat_ver="$(pyodide config get pyodide_abi_version)"
+          export MATURIN_PYEMSCRIPTEN_PLATFORM_VERSION="$plat_ver"
+          uvx 'maturin>=1.13.2' build --release \
             --target wasm32-unknown-emscripten \
             -i "$PYO3_PYTHON" \
             --compatibility off \
@@ -178,6 +184,9 @@ jobs:
           set -euo pipefail
           wheel="$(find "$PWD/dist-pyodide" -maxdepth 1 -name '*.whl' | head -n1)"
           [[ -n "$wheel" ]] || { echo "no wheel built" >&2; exit 1; }
+          # Guard against silently shipping a tag PyPI won't accept (PEP 783).
+          [[ "$(basename "$wheel")" =~ pyemscripten_[0-9]+_[0-9]+_wasm32\.whl$ ]] \
+            || { echo "wheel '$wheel' is not PEP 783 tagged" >&2; exit 1; }
           cd "$RUNNER_TEMP"
           npm init -y >/dev/null
           npm install --silent "pyodide@${PYODIDE_VERSION}"